Power Coupling Efficiency Enhancement in Multimode Step-Index Fiber Using Refractive and Diffractive Microlenses

<table>The power coupling efficiency <svg height="9.875" id="M140" style="vertical-align:-2.29482pt" version="1.1" viewbox="0 0 7.9375 9.875" width="7.9375" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,9.875)">
<g transform="translate(72,-64.1)">
<text transform="matrix(1,0,0,-1,-71.95,66.44)">
<tspan style="font-size: 12.50px; " x="0" y="0">𝜂</tspan>
</text>
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</svg> is shown as a function of fibre relative core-cladding refractive index difference <svg height="10.6625" id="M141" style="vertical-align:-0.0pt" version="1.1" viewbox="0 0 11.4125 10.6625" width="11.4125" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,10.6625)">
<g transform="translate(72,-63.47)">
<text transform="matrix(1,0,0,-1,-71.95,63.52)">
<tspan style="font-size: 12.50px; " x="0" y="0">Δ</tspan>
</text>
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</g>
</svg> in percent for different index mismatch <svg height="14.6875" id="M142" style="vertical-align:-3.2316pt" version="1.1" viewbox="0 0 17.112499 14.6875" width="17.112499" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,14.6875)">
<g transform="translate(72,-60.25)">
<text transform="matrix(1,0,0,-1,-71.95,63.52)">
<tspan style="font-size: 12.50px; " x="0" y="0">Δ</tspan>
</text>
<text transform="matrix(1,0,0,-1,-62.92,60.4)">
<tspan style="font-size: 8.75px; " x="0" y="0">𝑐</tspan>
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</g>
</g>
</svg>.</table>

International Journal of Optics

fig6

Figure 6

Figure 6: Power Coupling Efficiency Enhancement in Multimode Step-Index Fiber Using Refractive and Diffractive Microlenses 